The Steamship Authority, which handles ferries for Nantucket and Martha's Vineyard, needs to take steps to restore public confidence after cancellations of hundreds of trips between Woods Hole and Vineyard Haven, according to two Massachusetts lawmakers who represent the area.

State Sen. Julian Cyr and state Rep. Dylan Fernandes this week sent a letter to the general manager of the Steamship Authority, citing its failure to solve maintenance and operations problems and urging the authority to hire an outside consultant for a comprehensive review.

The ferry system carries residents to jobs and appointments, as well as hundreds of thousands of visitors during the summer. An internal Steamship Authority report tallied the number of canceled trips on the Martha's Vineyard route in the first four months of this year at 549 cancellations.

"With the most recent mechanical failure happening just last weekend, it is looking less like an isolated problem, which is extremely troubling given that we are on the cusp of the busy season," Cyr and Fernandes wrote.

The operational and mechanical failures have led to unreliable service, as well as a lack of transparency and communications with passengers and local residents, they added.

Officials with Gov. Charlie Baker's administration have also reached out to the authority.

"The Baker-Polito Administration contacted the Steam Ship Authority to offer assistance and will continue communicating with their office as they work to return full ferry service to the people of Martha's Vineyard," Brendan Moss, Baker's press secretary, said in an emailed statement.

The state doesn't have any appointment powers or direct oversight of the authority, which has operating revenues of $80 million and employs about 750 people during the peak season.

Along with hiring an outside consultant, Cyr and Fernandes, the two state lawmakers, also ask the authority to share contingency plans for future mechanical or operational failures, to hire a full-time communications manager and to hold a hearing on Martha's Vineyard to hear the frustrations of island residents.

"We appreciate and respect the hard work the Steamship Authority's management and its employees have done to mitigate recent service problems, but the time has come for more systemic action to restore public confidence in your organization," the lawmakers wrote.

Marc Hanover, the Martha's Vineyard representative on the Steamship Authority, has pressed for the hiring of McKinsey, the global management consulting firm, though other board members and authority staff have pushed back, saying many of the issues can be handled internally at a lower cost.

Steamship Authority staffers have already proposed hiring a communications director and setting up an operations and communications center inside the administrative offices in Falmouth.